Thank you all for responding! I know I have time for my biological clock to start ticking or whatever the stereotype is... but I've never felt a desire to have children. As selfish as it may sound, the only reasons I could come up with for really wanting to have a child personally were so I could give it a beautiful name (I love picking out baby names for some reason) and so I could see what my child would look like. Obviously not good reasons to produce offspring!
Still, I feel on the fence about it. I love the large family I come from and sometimes I think it'd be nice to continue that. My mom wants grandkids. Some say having a child is the greatest joy (though my mom says really it's more of a double edged sword ^_^).
However I can't think about it in terms of others, I need to consider myself. Unless my personality or desires were to change drastically in the future I just don't see myself wanting to have kids. I'm a really paranoid person and I think it would just stress me out too much to worry about them! Also I require a lot of 'me' time - having kids wouldn't allow for that. I just have so many things I'd like to do to make my life fulfilling and having kids is not one of those things I've ever thought of as a milestone in my life.
Ingilbert, I guess I could take my childhood activities as a clue as well... I had no interest in being a mommy, I was either coloring or pretending to be a mermaid in my grandparents' pool! I don't remember playing with dolls...
Thank you again for the responses, made me feel better about not wanting to have kids ^_^.